Ive searched for an issue close to mine with no success. If possible I need identification of the brake system.. I don’t see any markings on them. All I know of the kart so far is that is a Hasse frame and a YZ125 motor.

The actual issue is the brake don’t work anymore. The pedal does cause the calipers to move but barely and they don’t actually grab the rotors. I was going to bleed them but don’t see any bleeder screws on them. Also there are two master cylinders, when I pump the brakes a few times they seem to get out of sync maybe they just need to be bled but I’m stuck at this point.

You bleed it by removing the little screw between the brake line and the return spring. There’s one on each side of the rear caliper. For the front caliper you’re on your own until I get a better pic but it might be that big screw right on top.

Then you need a way to force or gravity feed brake fluid into the master cylinders. An old mustard bottle full of DOT3 works.

The linkage to the master cylinder is a bias adjuster, it’s going to be different from one side to the other and it will flop all over the place with all that air in the system.

Please make sure the bolts holding the calipers to the frame are high tensile strength and not stove bolts and why is there an elbow coming off the rear master cylinder and not a straight fitting?

You bleed it by removing the little screw between the brake line and the return spring. There’s one on each side of the rear caliper. For the front caliper you’re on your own until I get a better pic but it might be that big screw right on top.

Then you need a way to force or gravity feed brake fluid into the master cylinders. An old mustard bottle full of DOT3 works.

The linkage to the master cylinder is a bias adjuster, it’s going to be different from one side to the other and it will flop all over the place with all that air in the system.

Please make sure the bolts holding the calipers to the frame are high tensile strength and not stove bolts and why is there an elbow coming off the rear master cylinder and not a straight fitting?

Brakes look like early righetti ridolfi?

Gif

Thanks for the response!
On the rear brake caliper bleeder screw I believe your speaking of I see one between the brake line and return spring I also see on below the brake line as well.. there are two on the other side as well. Is there a procedure to opening them?

Ill check on the bolts holding the calipers in, just got the kart so ill add it the list haha. As for the elbow on coming off the master cylinder I’m not sure Ill check that out tomorrow.

Once I get a response on the front Ill go ahead and give a shot at bleeding the system and see what happens. Is it possible the seals in the master cylinders have gone bad and not allowing pressure to build up? No brake fluid leaks anywhere and the master cylinders are topped up when I pulled the screws out.. just doesn’t seem that likely that air found its way into the system. Either way its going to get bled. Thanks again!

Go to the store and buy a turkey baster, remove the rubber squeeze ball on top and throw it away

Remove the top screw at rear master cylinder/pump, turn and screw in tip of turkey baster

Fill it up like a funnel, all the way to the top

Remove the top screws Walt said at the rear calipers, you can only bleed the top ones

Pick up the kart from the front and put a 4×4 under the frame to create higher level

Let the fluid run at the caliper top bolts and pay close attention to the turkey baster, not to run dry. I would run 2 cycles of the funnel to clean all that junk out, and to make sure no more air is in the system.

Put the screw back in at the top part whichever rear caliper you decided to bleed first

Repeat the same procedure at the other side caliper.

Seal the other side caliper bleed screw when done, please remember never to run the turkey baster funnel dry, in fact when you’re done, please make sure there’s a bit left inside of it, so that when you remove funnel it will drain out of it, rather than not having enough fluid and letting air into the master cylinder.

When turkey baster/funnel removed, please re install filler screw back to master cylinder, make sure no debris goes inside, and pay attention so that washer or seal is still in good shape

Rear brake system completed, Congratulations, now move on to front brake system: